Background Information—Organs in the human body, such as the brain, kidney and heart, are maintained at a constant temperature of approximately 37° C. Hypothernia can be clinically defined as a core body temperature of 35° C. or less. Hypothermia is sometimes characterized further according to its severity. A body core temperature in the range of 33° C. to 35° C. is described as mild hypothermia. A body temperature of 28° C. to 32° C. is described as moderate hypothermia. A body core temperature in the range of 24° C. to 28° C. is described as severe hypothermia.
Hypothermia is uniquely effective in reducing ischemia. For example, it is effective in reducing brain injury caused by a variety of neurological insults and may eventually play an important role in emergency brain resuscitation. Experimental evidence has demonstrated that cerebral cooling improves outcome after global ischemia, focal ischemia, or traumatic brain injury. For this reason, hypothermia may be induced in order to reduce the effect of certain bodily injuries to the brain as well as ischemic injuries to other organs.